Yes, the heart, bones and muscle get a lot weaker. The immune system becomes less effective. But if you are in microgravity, where they are needed much less, and UV lamps can be used to sterilize everything left and right, the limited body functionality seems tolerable.

If hundreds of millions of dollars are involved, keep the person alive in a hospital with multiple doctors hired to look solely after the astronaut, upon return to Earth.

Hell, if cancer from radiation is a big concern, in spite of being inside of Earth's magnetosphere, the astronaut can undergo thorough cancer screening every month for the rest of their life.

I would like to know what health problems would make an astronaut after a decade in LEO and microgravity less than, lets say 1/4 as productive, as an astronaut fresh from Earth. This is presuming medicines can be brought up from Earth.

Good luck with finding someone who will be willing to volunteer for that one! What you are basically saying is "Hi Dude, we are going to f**k over your entire life, so we can make a bit more profit".

This seems to be all argued from the concept that people on the ISS are doing important work, which I have not seen demonstrated.

The ISS, like our bases in Antarctica, exist for geopolitical reasons. Some science is done, but as a byproduct. Think of it this way: a laboratory is full of scientists and researchers. A military base is full of people in the military, plus some support crew. Here's the current crew on the ISS, you figure out what the place is:

*US Air Force test pilot with degrees in systems engineering.*US Coast Guard with aeronautical degree.*Russian Air Force pilot/engineer, son of prior cosmonaut.*Russian Air Force fighter pilot.*Russian Air Force pilot/engineer.*Japanese surgeon.

You can apply the same test to Apollo. See how many geologists were sent, compare to the number of test pilots.

Isn't that also a sign of how immature our space technology really is? The first aeroplanes didn't carry many passengers either, and the pilots were very busy just keeping them airborne. The Space Shuttle Orbiter is arguably the most advanced space craft we've built so far, and it had room for at most five "passengers", mostly engineers that worked on other technology up there. Today's space tourists need a lot of training and then to help fly their space craft if they want to go into space.

When/if the technology gets to the point where you can just walk up to the rocket, strap in, and fly to a space station that is being maintained by a separate crew and as easy to use as an aeroplane cabin, scientists can fly much more easily. Meanwhile, the scientists stay on the ground and have the on-site engineers at the space station push the buttons on their experiments.

_________________Say, can you feel the thunder in the air? Just like the moment ’fore it hits – then it’s everywhereWhat is this spell we’re under, do you care? The might to rise above it is now within your sphereMachinae Supremacy – Sid Icarus

@Ben, I actually thought that all the astronauts were scientist, apart perhaps one pilot.

But at least the engineers and scientists on the ground get to test the flight specific hardware, however the Soyuz may be thoroughly tested already, it is kind of sad that the space station is not used to the it full potential.

Well soon we will have the private space stations, I'm sure that the (expensive) crew at those will not waste their time on prestige, but rather on practical science that can be converted into money.

Do you have a link to that? The closest thing I could find was a centrifuge that two astronauts would strap into, and they would spin for an hour. It looks like they studied this approach in Houston for a while, but scrapped the idea.

Don't know if it was scrapped or not, but it was proposed earlier this year by a NASA team.

Question: Do we have the resources?-Answer: Yes-Question: Do we have the technology?-Answer: Yes-Question: Do we have enough people with motivation?-Answer: Yes-Do we have control over whether we can do it or not?-Answer: NO----------------

We have everything we need to send more astronauts to the ISS, and yes, we do even have the technology to create an artificial gravity.

Due to people in certain places though, we will never be able to see this happen, maybe we should all get together by the millions and demand our rights to further our exploration?